The Giant VHF Radio Telescope in India has captured a radio signal from the furthest galaxy never captured from Land. A sign that was born ago 8.8 billion years.
It is a shock to discover that most of the stars we see in the sky are dead. This is because they are so far away that their light takes billions of years to reach Earth. So when we receive it, possibly that star that emitted the light no longer exists.
This is what surely has happened with the galaxy SDSSJ0826+5630located at 8.8 billion light years from Earth. A distance almost impossible to imagine.
A galaxy far, far away
All galaxies produce electromagnetic emissions either lightin a wide range of wavelengths, as explained by Space.com. But there is a special wavelength known as “21 centimeter line” either “hydrogen line“, which records the neutral atoms of hydrogen.
Until now through this wavelength astronomers have only been able to capture signals from nearby galaxies. But new discoveries, like that of the gravitational lensingallow to detect signals much further away using current ground-based telescopes.
The radio broadcasts they lose strength with distance, but the effect of gravitational lensing means that, when the emissions of a galaxy intersect with another galaxy, the gravitational forces produce a lens effect that magnifies signal up to 30 times. This allows very distant signals to travel great distances.
This is what has happened with the captured signal of the galaxy SDSSJ0826+5630who was born ago 8.8 billion years, when the galaxies and stars were “young”. It is a unique opportunity to study the origins of the universeof which we still know little.
Astronomers have been able to measure the gas content of the galaxy through this hydrogen signal, and have discovered that its mass is twice that of the first stars visible in our own galaxy.
catch a so far signal From a telescope on earth, is a milestone. But just a few days after the announcement, the james webb telescope, more modern and without the interference of pollution and excess terrestrial light, has captured the emissions of a galaxy from 13,400 million years ago. That is almost the origin of the universe, whose age is estimated to be about 13.7 billion years.
New discoveries, and new technologies, already allow us to capture radio signals of galaxies of ago 8 billion yearswithout leaving the Land. The secrets of our own origin await us.